Papers for Wednesday, Apr 05 2023

An accurate solar wind speed model is important for space weather predictions, catastrophic event warnings, and other issues concerning solar wind - magnetosphere interaction. In this work, we construct a model based on convolutional neural network (CNN) and Potential Field Source Surface (PFSS) magnetograms, considering a solar wind source surface of $R_{\rm SS}=2.5R_\odot$, aiming to predict the solar wind speed at the Lagrange 1 (L1) point of the Sun-Earth system. The input of our model consists of four Potential Field Source Surface (PFSS) magnetograms at $R_{\rm SS}$, which are 7, 6, 5, and 4 days before the target epoch. Reduced magnetograms are used to promote the model's efficiency. We use the Global Oscillation Network Group (GONG) photospheric magnetograms and the potential field extrapolation model to generate PFSS magnetograms at the source surface. The model provides predictions of the continuous test dataset with an averaged correlation coefficient (CC) of 0.52 and a root mean square error (RMSE) of 80.8 km/s in an eight-fold validation training scheme with the time resolution of the data as small as one hour. The model also has the potential to forecast high speed streams of the solar wind, which can be quantified with a general threat score of 0.39.

Aims. The treatment of astronomical image time series has won increasing attention in recent years. Indeed, numerous surveys following up on transient objects are in progress or under construction, such as the Vera Rubin Observatory Legacy Survey for Space and Time (LSST), which is poised to produce huge amounts of these time series. The associated scientific topics are extensive, ranging from the study of objects in our galaxy to the observation of the most distant supernovae for measuring the expansion of the universe. With such a large amount of data available, the need for robust automatic tools to detect and classify celestial objects is growing steadily. Methods. This study is based on the assumption that astronomical images contain more information than light curves. In this paper, we propose a novel approach based on deep learning for classifying different types of space objects directly using images. We named our approach ConvEntion, which stands for CONVolutional attENTION. It is based on convolutions and transformers, which are new approaches for the treatment of astronomical image time series. Our solution integrates spatio-temporal features and can be applied to various types of image datasets with any number of bands. Results. In this work, we solved various problems the datasets tend to suffer from and we present new results for classifications using astronomical image time series with an increase in accuracy of 13%, compared to state-of-the-art approaches that use image time series, and a 12% increase, compared to approaches that use light curves.

We revisit the scenario of primordial black hole (PBH) formation from large curvature perturbations generated during the waterfall phase transition in hybrid inflation models. In a minimal setup considered in the literature, the mass and abundance of PBHs are correlated and astrophysical size PBHs tend to be overproduced. This is because a longer length scale for curvature perturbations (or a larger PBH mass) requires a longer waterfall regime with a flatter potential, which results in overproduction of curvature perturbations. However, in this paper, we discuss that the higher-dimensional terms for the inflaton potential affect the dynamics during the waterfall phase transition and show that astrophysical size PHBs of order $10^{17\text{--}23} \, {\rm g}$ (which can explain the whole dark matter) can form in some parameter space consistently with any existing constraints. The scenario can be tested by observing the induced gravitational waves from scalar perturbations by future gravitational wave experiments, such as LISA.

Accretion disc model fitting to optical/UV quasar spectra requires that the highest mass black holes have the highest spin, with implications on the hierarchical growth of supermassive black holes and their host galaxies over cosmic time. However, these accretion disc models did not include the effects of relativistic ray tracing. Here we show that gravitational redshift cancels out most of the increase in temperature and luminosity from the smaller radii characteristic of high spin. These self consistent accretion disc models do not fit the UV spectra of the most massive quasars ($\log M/M_{\odot} \geq 9.5$), most likely showing that the disc structure is very different to that assumed. We extend the relativistic ray tracing on more complex disc models, where the emission is not limited to (colour temperature corrected) black body radiation but can instead be emitted as warm and hot Comptonisation. We demonstrate this on the broadband (UV/X-ray) spectrum of Fairall 9, a local intensively monitored 'bare' AGN (no significant intrinsic cold or warm absorption). We show that including relativistic corrections does make a difference even to these more complex models, but caution that the inferred black hole spin depends on the assumed nature and geometry of the accretion flow. Additionally, we make our model code publicly available, and name it RELAGN.

We model the collision of molecular clouds to investigate the role of the initial properties on the remnants. Our clouds collide and evolve in a background medium that is approximately ten times less dense than the clouds, and we show that this relatively dense background is dynamically important for the evolution of the collision remnants. Given the motion of the clouds and the remnants through the background, we develop, implement, and introduce dynamic boundary conditions. We investigate the effect of the initial cloud mass, velocity, internal turbulence, and impact angle. The initial velocity and its velocity components have the largest affect on the remnant. This affects the spatial extent of the remnant, which affects the number of resulting star clusters and the distribution of their masses. The less extended remnants tend to have fewer, but more massive, clusters. Unlike the clusters, the gas distributions are relatively insensitive to the initial conditions, both the distribution of the bulk gas properties and the gas clumps. In general, cloud collisions are relatively insensitive to their initial conditions when modelled hydrodynamically in a dynamically important background medium.

The role of large-scale bars in the fuelling of active galactic nuclei (AGN) is still debated, even as evidence mounts that black hole growth in the absence of galaxy mergers cumulatively dominated and may substantially influence disc (i.e., merger-free) galaxy evolution. We investigate whether large-scale galactic bars are a good candidate for merger-free AGN fuelling. Specifically, we combine slit spectroscopy and Hubble Space Telescope imagery to characterise star formation rates (SFRs) and stellar masses of the unambiguously disc-dominated host galaxies of a sample of luminous, Type-1 AGN with 0.02 < z 0.024. After carefully correcting for AGN signal, we find no clear difference in SFR between AGN hosts and a stellar mass-matched sample of galaxies lacking an AGN (0.013 < z < 0.19), although this could be due to a small sample size (n_AGN = 34). We correct for SFR and stellar mass to minimise selection biases, and compare the bar fraction in the two samples. We find that AGN are marginally (1.7$\sigma$) more likely to host a bar than inactive galaxies, with AGN hosts having a bar fraction, fbar = 0.59^{+0.08}_{-0.09} and inactive galaxies having a bar fraction fbar = 0.44^{+0.08}_{-0.09}. However, we find no further differences between SFR- and mass-matched AGN and inactive samples. While bars could potentially trigger AGN activity, they appear to have no further, unique effect on a galaxy's stellar mass or SFR.

The Galactic flux of cosmic-ray (CR) positrons in the GeV to TeV energy range is very likely due to different Galactic components. One of these is the inelastic scattering of CR nuclei with the atoms of the interstellar medium. The precise amount of this component determines the eventual contribution from other sources. We present here a new estimation of the secondary CR positron flux by incorporating the latest results for the production cross sections of $e^\pm$ from hadronic scatterings calibrated on collider data. All the reactions for CR nuclei up to silicon scattering on both hydrogen and helium are included. The propagation models are derived consistently by fits on primary and secondary CR nuclei data. Models with a small halo size ($\leq 2$ kpc) are disfavored by the nuclei data although the current uncertainties on the beryllium nuclear cross sections may impact this result. The resulting positron flux shows a strong dependence on the Galactic halo. Within the most reliable propagation models, the positron flux matches the data for energies below 1 GeV. We verify that secondary positrons contribute less than $70\%$ of the data already above a few GeV, demonstrating that an excess of positrons is already present at very low energies. At larger energies, our predictions are below the data with the discrepancy becoming more pronounced. Our predictions are provided together with uncertainties due to propagation and hadronic cross sections. In addition to the predictions of positrons, we provide new predictions also for the secondary CR electron flux.

Observations of gravitational waves (GWs) from merging compact binaries have become a regular occurrence. The continued advancement of the LIGO-Virgo-KAGRA (LVK) Collaboration detectors have now produced a catalog of over 90 such mergers, from which we can begin to uncover the formation history of merging compact binaries. In this work, we search for subpopulations in the LVK's third gravitational wave transient catalog (GWTC-3) by incorporating discrete latent variables in the hierarchical Bayesian inference framework to probabilistically assign each BBH observation into separate categories associated with distinctly different population distributions. By incorporating formation channel knowledge within the mass and spin correlations found in each category, we find an over density of mergers with a primary mass of $\sim10 M_\odot$, consistent with isolated binary formation. This low-mass subpopulation has a spin magnitude distribution peaking at $a_\mathrm{peak}=0.16^{0.19}_{-0.16}$, exhibits spins preferentially aligned with the binary's orbital angular momentum, is constrained by $15^{+0.0}_{-1.0}$ of our observations, and contributes $82\%^{+8.0\%}_{-16\%}$ to the overall population of BBHs. Additionally, we find that the component of the mass distribution containing the previously identified $35M_\odot$ peak has spins consistent with the $10M_\odot$ events, with $99\%$ of primary masses less than $m_{1,99\%} = 49^{+25}_{-8.1} M_\odot$, providing an estimate of the lower edge of the theorized pair instability mass gap. This work is a first step in gaining a deeper understanding of compact binary formation and evolution, and will provide more robust conclusions as the catalog of observations becomes larger.

We use the PyNeb 1.1.16 Python package to evaluate the atomic datasets available for the spectral modeling of [Fe II] and [Fe III], which list level energies, A-values, and effective collision strengths. Most datasets are reconstructed from the sources, and new ones are incorporated to be compared with observed and measured benchmarks. For [Fe III], we arrive at conclusive results that allow us to select the default datasets, while for [Fe II], the conspicuous temperature dependency on the collisional data becomes a deterrent. This dependency is mainly due to the singularly low critical density of the $\mathrm{3d^7\ a\,^4F_{9/2}}$ metastable level that strongly depends on both the radiative and collisional data, although the level populating by fluorescence pumping from the stellar continuum cannot be ruled out. A new version of PyNeb (1.1.17) is released containing the evaluated datasets.

Dynamical masses of giant planets and brown dwarfs are critical tools for empirically validating substellar evolutionary models and their underlying assumptions. We present a measurement of the dynamical mass and an updated orbit of PZ Tel B, a young brown dwarf companion orbiting a late-G member of the $\beta$ Pic moving group. PZ Tel A exhibits an astrometric acceleration between Hipparcos and Gaia EDR3, which enables the direct determination of the companion's mass. We have also acquired new Keck/NIRC2 adaptive optics imaging of the system, which increases the total baseline of relative astrometry to 15 years. Our joint orbit fit yields a dynamical mass of $27^{+25}_{-9} \, M_{\mathrm{Jup}}$, semi-major axis of $27^{+14}_{-4} \, \mathrm{au}$, eccentricity of $0.52^{+0.08}_{-0.10}$, and inclination of $91.73^{+0.36}_{-0.32} {}^\circ$. The companion's mass is consistent within $1.1\sigma$ of predictions from four grids of hot-start evolutionary models. The joint orbit fit also indicates a more modest eccentricity of PZ Tel B than previous results. PZ Tel joins a small number of young (${<}200 \, \mathrm{Myr}$) systems with benchmark substellar companions that have dynamical masses and precise ages from moving group membership.

The microlensing signal in the light curves of gravitationally lensed quasars can shed light on the dark matter (DM) composition in their lensing galaxies. Here, we investigate a sample of six lensed quasars from the most recent and best COSMOGRAIL observations: HE~1104$-$1805, HE~0435$-$1223, RX~J1131$-$1231, WFI~2033$-$4723, PG~1115$+$080, and J1206$+$4332, yielding a total of eight microlensing light curves, when combining independent image pairs and typically spanning ten years. We explore the microlensing signals to determine whether the standard assumptions on the stellar populations are sufficient to account for the amplitudes of the measured signals. We use the most detailed lens models to date from the H0LiCOW/TDCOSMO collaboration to generate simulated microlensing light curves. Finally, we propose a methodology based on the Kolmogorov-Smirnov test to verify whether the observed microlensing amplitudes in our data are compatible with the most standard scenario, whereby galaxies are composed of stars as compact bodies and smoothly distributed DM. Given our current sample, we show that the standard scenario cannot be rejected, in contrast with previous results by Hawkins (2020a), claiming that a population of stellar mass primordial black holes (PBHs) is necessary to explain the amplitude of the microlensing signals in lensed quasar light curves. We further estimate the number of microlensing light curves needed to distinguish between the standard scenario with stellar microlensing and a scenario that describes all the DM contained in galaxies in the form of compact objects such as PBHs, with a mean mass of $0.2M_{\odot}$. We find that about 900 microlensing curves from the Rubin Observatory will be sufficient to discriminate between the two extreme scenarios at a 95\% confidence level.

Einstein Telescope (ET) is a proposed third generation, wide-band gravitational wave (GW) detector. Given its improved detection sensitivity in comparison to the second generation detectors, it will be capable of exploring the universe with GWs up to very high redshifts. In this paper we present the algorithm to answer three main questions regarding the star formation rate density (SFR) (i) when did the formation terminate?, (ii) at what redshift does the SFR peak?, and finally (iii) what is the functional form of SFR at high redshift? for a given population. We present an algorithm to infer the functional form of SFR for different populations of compact binaries originating in stars from Population (Pop) I+II and Pop III, using ET as a single instrument. We show that the reconstruction of SFR is essentially independent of the time delay distributions up to $z \sim 14$ and the accuracy of the reconstruction strongly depends on the time delay distribution only at high redshifts of $z\gtrsim 14$. We define the termination redshift as the redshift where the SFR drops to 1\% of its peak value. In this analysis we constrain the peak of the SFR as a function of redshift and show that ET as a single instrument can distinguish the termination redshifts of different SFRs. The accurate estimate of the termination redshift depends on correctly modelling the tail of the time delay distribution representing delay time $\gtrsim 8$ Gyr.

Long Gamma Ray Bursts (GRBs) originate from the collapse of massive, rotating stars. We aim to model the process of stellar collapse in the scenario of a self-gravitating collapsing star. We account for the changes in Kerr metric induced by the growth of the black hole, accretion of angular momentum, as well as the self-gravity effect due to a large mass of the collapsing stellar core falling onto black hole in a very short time. We also investigate the existence of accretion shocks in the collapsar, and role of magnetic field in their propagation. We compute the time-dependent axially-symmetric General Relativistic magnetohydrodynamic model of a collapsing stellar core in the dynamical Kerr metric. We explore the influence of self-gravity in such star, where the newly formed black hole is increasing the mass, and changing its spin. The Kerr metric evolves according to the mass and angular momentum changes during the collapse. We parameterize the rotation inside the star, and account for the presence of large-scale poloidal magnetic field. For the set of the global parameters, such as the initial black hole spin, and initial content of specific angular momentum in the stellar envelope, we determine the evolution of black hole parameters (mass and spin) and we quantify the strength of the gravitational instability, variability timescales and amplitudes. We find that the role of the gravitational instability measured by the value of the Toomre parameter is relatively important in the innermost regions of the collapsing star. The character of accretion rate variability strongly depends on the assumption of self-gravity in the model, and is also affected by the magnetic field. Additional factors are initial spin and rotation of the stellar core.

Silicon-based dielectric is crucial for many superconducting devices, including high-frequency transmission lines, filters, and resonators. Defects and contaminants in the amorphous dielectric and at the interfaces between the dielectric and metal layers can cause microwave losses and degrade device performance. Optimization of the dielectric fabrication, device structure, and surface morphology can help mitigate this problem. We present the fabrication of silicon oxide and nitride thin film dielectrics. We then characterized them using Scanning Electron Microscopy, Atomic Force Microscopy, and spectrophotometry techniques. The samples were synthesized using various deposition methods, including Plasma-Enhanced Chemical Vapor Deposition and magnetron sputtering. The films morphology and structure were modified by adjusting the deposition pressure and gas flow. The resulting films were used in superconducting resonant systems consisting of planar inductors and capacitors. Measurements of the resonator properties, including their quality factor, were performed.

Extracting information from cosmic surveys is often done in a two-step process, construction of maps and then summary statistics such as two-point functions. We use simulations to demonstrate the advantages of a general Bayesian framework that consistently combines different cosmological experiments on the field level, and reconstructs both the maps and cosmological parameters. We apply our method to jointly reconstruct the primordial CMB, the Integrated Sachs Wolfe effect, and 6 tomographic galaxy density maps on the full sky on large scales along with several cosmological parameters. While the traditional maximum a posterior estimator has both 2-point level and field-level bias, the new approach yields unbiased cosmological constraints and improves the signal-to-noise ratio of the maps.

We present our fifth set of results from our mid-infrared imaging survey of Milky Way Giant HII (GHII) regions with our detailed analysis of DR7 and K3-50. We obtained 20/25 and 37um imaging maps of both regions using the FORCAST instrument on the Stratospheric Observatory For Infrared Astronomy (SOFIA). We investigate the multi-scale properties of DR7 and K3-50 using our data in conjunction with previous multi-wavelength observations. Near to far-infrared spectral energy distributions of individual compact infrared sources were constructed and fitted with massive young stellar object (MYSO) models. We find eight out of the ten (80%) compact sources in K3-50 and three out of the four (75%) sources in DR7 are likely to be MYSOs. We derived luminosity-to-mass ratios of the extended radio sub-regions of DR7 and K3-50 to estimate their relative ages. The large spread in evolutionary state for the sub-regions in K3-50 likely indicates that the star-forming complex has undergone multiple star-forming events separated more widely in time, whereas the smaller spread in DR7 likely indicates the star formation sub-regions are more co-eval. DR7 and K3-50 have Lyman continuum photon rates just above the formal threshold criterion for being categorized as a GHII region (10^50 photons/s) but with large enough errors that this classification is uncertain. By measuring other observational characteristics in the infrared, we find that K3-50 has properties more akin to previous bona fide GHII regions we have studied, whereas DR7 has values more like those of the non-GHII regions we have previously studied.

Ly$\alpha$ emission is possibly the best indirect diagnostic of Lyman continuum (LyC) escape since the conditions that favor the escape of Ly$\alpha$ photons are often the same that allows for the escape of LyC photons. In this work, we present the rest UV-optical spectral characteristics of 11 Ly$\alpha$ emitting galaxies at 3 $<$ z $<$ 6 - the optimal redshift range chosen to avoid the extreme IGM attenuation while simultaneously studying galaxies close enough to the epoch of reionization. From a combined analysis of JWST/NIRSpec and MUSE data, we present the Ly$\alpha$ escape fraction and study their correlations with other physical properties of galaxies that might facilitate Ly$\alpha$ escape. We find that our galaxies have low masses (80\% of the sample with $\rm log_{10} \ M_{\star} < 9.5\ M_{\odot}$), compact sizes (median $\rm R_e \sim 0.7 \ kpc $), low dust content, moderate [OIII]/[OII] flux ratios (mean $\sim$ 6.8 $\pm$ 1.2), and moderate Ly$\alpha$ escape fraction (mean $\rm f_{esc}^{Ly\alpha} \ \sim$ 0.11). Our sample show characteristics that are broadly consistent with the low redshift galaxies with Ly$\alpha$ emission, which are termed as "analogs" of high redshift population. We predict the Lyman continuum escape fraction in our sample to be low (0.03-0.07), although larger samples in the post-reionization epoch are needed to confirm these trends.

We have demonstrated the fabrication of a monolithic, 5-meter diameter, aluminum reflector with 17.4 $\mu$m RMS surface error. The reflector was designed to avoid the problem of pickup due to scattering from panel gaps in a large, millimeter-wavelength telescope that will be used for measurements on the cosmic microwave background.

New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented, which contribute major progress to our understanding of the morpho-kinematics of the circumstellar envelope (CSE). The birth of the equatorial density enhancement (EDE) is shown to occur very close to the star where evidence for rotation has been obtained. High Doppler velocity wings are seen to consist of two components, the front end of the global wind, reaching above $\pm$12 \kms, and an effective line broadening, confined within 200 mas from the centre of the star, reaching above $\pm$20 \kms\ and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell granulation. Close to the star, episodic and lumpy mass ejections are observed, and their interaction with the gas of the nascent EDE, first rotating and later slowly expanding, is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8-10 \kms\ on the polar symmetry axis to $\sim$2 \kms\ at the equator. It implies a very complex morpho-kinematics, which prevents making reliable interpretations with reasonable confidence. In particular, it sheds serious doubts on an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of $\sim$0.4 arcsec from its centre and currently west of it.

The solar atmosphere shows anomalous variation in temperature, starting from the 5500 K photosphere to the million-degree Kelvin corona. The corona itself expands into the interstellar medium as the free streaming solar wind, which modulates and impacts the near-Earth space weather. The precise source regions of different structures in the solar wind, their formation height, and the heating of the solar atmosphere are inextricably linked and unsolved problems in astrophysics. Observations suggest correlations between Coronal holes (CHs), which are cool, intensity deficit structures in the solar corona, with structures in the solar wind. Observations also suggest the local plasma heating in the corona through power-law distributed impulsive events. In this thesis, we use narrowband photometric, spectroscopic, and disc-integrated emission of the solar atmosphere ranging from Near Ultraviolet to X-rays along with in-situ solar wind measurements to understand (i). the source regions of the solar wind, (ii). the underlying mechanism of solar coronal heating, and (iii). the differentiation in dynamics of CHs with the background Quiet Sun (QS) regions, which do not show any significant signature of the solar wind. We leverage machine learning and numerical modeling tools to develop solar wind forecasting codes using interpretable AI, inversion codes to infer the properties of impulsive events and to understand the differences in the thermodynamics of CHs and QS regions. We finally present a unified scenario of solar wind emergence and heating in the solar atmosphere and discuss the implications of inferences from this thesis.

Asteroseismology is playing an increasingly important role in the characterization of red-giant host stars and their planetary systems. Here, we conduct detailed asteroseismic modeling of the evolved red-giant branch (RGB) hosts KOI-3886 and $\iota$ Draconis, making use of end-of-mission Kepler (KOI-3886) and multi-sector TESS ($\iota$ Draconis) time-series photometry. We also model the benchmark star KIC 8410637, a member of an eclipsing binary, thus providing a direct test to the seismic determination. We test the impact of adopting different sets of observed modes as seismic constraints. Inclusion of $\ell=1$ and 2 modes improves the precision on the stellar parameters, albeit marginally, compared to adopting radial modes alone, with $1.9$-$3.0\%$ (radius), $5$-$9\%$ (mass), and $19$-$25\%$ (age) reached when using all p-dominated modes as constraints. Given the very small spacing of adjacent dipole mixed modes in evolved RGB stars, the sparse set of observed g-dominated modes is not able to provide extra constraints, further leading to highly multimodal posteriors. Access to multi-year time-series photometry does not improve matters, with detailed modeling of evolved RGB stars based on (lower-resolution) TESS data sets attaining a precision commensurate with that based on end-of-mission Kepler data. Furthermore, we test the impact of varying the atmospheric boundary condition in our stellar models. We find mass and radius estimates to be insensitive to the description of the near-surface layers, at the expense of substantially changing both the near-surface structure of the best-fitting models and the values of associated parameters like the initial helium abundance, $Y_{\rm i}$. Attempts to measure $Y_{\rm i}$ from seismic modeling of red giants may thus be systematically dependent on the choice of atmospheric physics.

Employing the spherical collapse (SC) formalism, we investigate the linear evolution of the matter overdensity for energy-momentum-squared gravity (EMSG) which in practical phenomenological terms, one may imagine as an extension of \LambdaCDM model of cosmology. The underlying model while still having a cosmological constant, is a nonlinear matter extension of the general theory of relativity and includes modification terms dominating in the high energy regimes i.e., early universe. Considering the Friedman-Robertson-Walker (FRW) background in the presence of a cosmological constant, we find the effects of the modifications arising from EMSG on the growth of perturbations at the early stages of the universe. By taking into account both possible negative, and positive values of the model parameter of EMSG, we discuss its role in the evolution of the matter density contrast and growth function in the level of linear perturbations. While EMSG leaves imprints distinguishable from \LambdaCDM, we find that the negative range of the ESMG model parameter is not well-behaved indicating an anomaly in the parameter space of the model. In this regard, for the evaluation of the galaxy cluster number count in the framework of EMSG, we equivalently provide an analysis of the number count of the gravitationally collapsed objects (or the dark matter halos). We show that the galaxy cluster number count decreases compared to the \LambdaCDM model. In agreement with the hierarchical model of structure formation, in EMSG cosmology also the more massive structures are less abundant, meaning that form at later times.

The crust of a neutron star is known to melt at a temperature that increases with increasing matter density, up to about $10^{10}$ K. At such high temperatures and beyond, the crustal ions are put into collective motion and the associated entropy contribution can affect both the thermodynamic properties and the composition of matter. We studied the importance of this effect in different thermodynamic conditions relevant to the inner crust of the proto-neutron star, both at beta equilibrium and in the fixed-proton-fraction regime. To this aim, we solved the hydrodynamic equations for an ion moving in an incompressible, irrotational, and non-viscous fluid, with different boundary conditions, thus leading to different prescriptions for the ion effective mass. We then employed a compressible liquid-drop approach in the one-component plasma approximation, including the renormalisation of the ion mass to account for the influence of the surrounding medium. We show that the cluster size is determined by the competition between the ion centre-of-mass motion and the interface properties, namely the Coulomb, surface, and curvature energies. In particular, including the translational free energy in the minimisation procedure can significantly reduce the optimal number of nucleons in the clusters and lead to an early dissolution of clusters in dense beta-equilibrated matter. On the other hand, we find that the impact of translational motion is reduced in scenarios where the proton fraction is assumed constant and is almost negligible on the inner-crust equation of state. Our results show that the translational degrees of freedom affect the equilibrium composition of beta-equilibrated matter and the density and pressure of the crust-core transition in a non-negligible way, highlighting the importance of its inclusion when modelling the finite-temperature inner crust of the (proto-)neutron star.

Alfv\'enic motions are ubiquitous in the solar atmosphere and their observed properties are closely linked to those of photospheric p-modes. However, it is still unclear how a predominantly acoustic wave driver can produce these transverse oscillations in the magnetically dominated solar corona. In this study we conduct a 3D ideal MHD numerical simulation to model a straight, expanding coronal loop in a gravitationally stratified solar atmosphere which includes a transition region and chromosphere. We implement a driver locally at one foot-point corresponding to an acoustic-gravity wave which is inclined by $\theta = 15^{\circ}$ with respect to the vertical axis of the magnetic structure and is similar to a vertical driver incident on an inclined loop. We show that transverse motions are produced in the magnetic loop, which displace the axis of the waveguide due to the breaking of azimuthal symmetry, and study the resulting modes in the theoretical framework of a magnetic cylinder model. By conducting an azimuthal Fourier analysis of the perturbed velocity signals, the contribution from different cylindrical modes is obtained. Furthermore, the perturbed vorticity is computed to demonstrate how the transverse motions manifest themselves throughout the whole non-uniform space. Finally we present some physical properties of the Alfv\'enic perturbations and present transverse motions with velocity amplitudes in the range of $0.2-0.75$ km s$^{-1}$ which exhibit two distinct oscillation regimes corresponding to $42$ s and $364$ s, where the latter value is close to the period of the p-mode driver in the simulation.

We introduce the state-of-the-art deep learning Denoising Diffusion Probabilistic Model (DDPM) as a method to infer the volume or number density of giant molecular clouds (GMCs) from projected mass surface density maps. We adopt magnetohydrodynamic simulations with different global magnetic field strengths and large-scale dynamics, i.e., noncolliding and colliding GMCs. We train a diffusion model on both mass surface density maps and their corresponding mass-weighted number density maps from different viewing angles for all the simulations. We compare the diffusion model performance with a more traditional empirical two-component and three-component power-law fitting method and with a more traditional neural network machine learning approach (CASI-2D). We conclude that the diffusion model achieves an order of magnitude improvement on the accuracy of predicting number density compared to that by other methods. We apply the diffusion method to some example astronomical column density maps of Taurus and the Infrared Dark Clouds (IRDCs) G28.37+0.07 and G35.39-0.33 to produce maps of their mean volume densities.

Gaia DR3 parallaxes are used to calibrate preliminary period--luminosity relations of O-rich Mira variables in the 2MASS $J$, $H$ and $K_s$ bands using a probabilistic model accounting for variations in the parallax zeropoint and underestimation of the parallax uncertainties. The derived relations are compared to those measured for the Large and Small Magellanic Clouds, the Sagittarius dwarf spheroidal galaxy, globular cluster members and the subset of Milky Way Mira variables with VLBI parallaxes. The Milky Way linear $JHK_s$ relations are slightly steeper and thus fainter at short period than the corresponding LMC relations suggesting population effects in the near-infrared are perhaps larger than previous observational works have claimed. Models of the Gaia astrometry for the Mira variables suggest that, despite the intrinsic photocentre wobble and use of mean photometry in the astrometric solution of the current data reduction, the recovered parallaxes should be on average unbiased but with underestimated uncertainties for the nearest stars. The recommended Gaia EDR3 parallax zeropoint corrections evaluated at $\nu_\mathrm{eff}=1.25\,\mu\mathrm{m}^{-1}$ require minimal ($\lesssim5\,\mu\mathrm{as}$) corrections for redder five-parameter sources, but over-correct the parallaxes for redder six-parameter sources, and the parallax uncertainties are underestimated, at most by a factor $\sim1.6$ at $G\approx12.5\,\mathrm{mag}$. The derived period--luminosity relations are used as anchors for the Mira variables in the Type Ia host galaxy NGC 1559 to find $H_0=(73.7\pm4.4)\,\mathrm{km\,s}^{-1}\mathrm{Mpc}^{-1}$.

Past computational studies of planet-induced vortices have shown that the dust asymmetries associated with these vortices can be long-lived enough that they should be much more common in mm/sub-mm observations of protoplanetary discs, even though they are quite rare. Observed asymmetries also have a range of azimuthal extents from compact to elongated even though computational studies have shown planet-induced vortices should be preferentially elongated. In this study, we use 2-D and 3-D hydrodynamic simulations to test whether those dust asymmetries should really be so long-lived or so elongated. With higher resolution (29 cells per scale height) than our previous work, we find that vortices can be more compact by developing compact cores when higher-mass planets cause them to re-form, or if they are seeded by tiny compact vortices from the vertical shear instability (VSI), but not through dust feedback in 3-D as was previously expected in general. Any case with a compact vortex or core(s) also has a longer lifetime. Even elongated vortices can have longer lifetimes with higher-mass planets or if the associated planet is allowed to migrate, the latter of which can cause the dust asymmetry to stop decaying as the planet migrates away from the vortex. These longer dust asymmetry lifetimes are even more inconsistent with observations, perhaps suggesting that discs still have an intermediate amount of effective viscosity.

We present the dynamical properties of 294 cores embedded in twelve IRDCs observed as part of the ASHES Survey. Protostellar cores have higher gas masses, surface densities, column densities, and volume densities than prestellar cores, indicating core mass growth from the prestellar to the protostellar phase. We find that ~80% of cores with virial parameter ($\alpha$) measurements are gravitationally bound ($\alpha$< 2). We also find an anti-correlation between the mass and the virial parameter of cores, with massive cores having on average lower virial parameters. Protostellar cores are more gravitationally bound than prestellar cores, with an average virial parameter of 1.2 and 1.5, respectively. The observed non-thermal velocity dispersion (from N$_{2}$D$^{+}$ or DCO$^{+}$) is consistent with simulations in which turbulence is continuously injected, whereas the core-to-core velocity dispersion is neither in agreement with driven nor decaying turbulence simulations. We find no significant increment in the line velocity dispersion from prestellar to protostellar cores, suggesting that dense gas within the core traced by these deuterated molecules is not yet severely affected by turbulence injected from outflow activity at the early evolutionary stages traced in ASHES. The most massive cores are strongly self-gravitating and have greater surface density, Mach number, and velocity dispersion than cores with lower masses. Dense cores have not significant velocity shifts relative to their low-density envelopes, suggesting that dense cores are co-moving with their envelopes. We conclude that the observed core properties are more in line with predictions of ``clump-fed" scenarios rather than with ``core-fed" scenarios.

The initial conditions found in infrared dark clouds (IRDCs) provide insights on how high-mass stars and stellar clusters form. We have conducted high-angular resolution and high-sensitivity observations toward thirty-nine massive IRDC clumps, which have been mosaicked using the 12m and 7m arrays from the Atacama Large Millimeter/submillimeter Array (ALMA). The targets are 70 $\mu$m dark massive (220-4900 $M_\odot$), dense ($>$10$^4$ cm$^{-3}$), and cold ($\sim$10-20K) clumps located at distances between 2 and 6 kpc. We identify an unprecedented number of 839 cores, with masses between 0.05 and 81 $M_\odot$ using 1.3 mm dust continuum emission. About 55% of the cores are low-mass ($<$1 $M_\odot$), whereas $\lesssim$1% (7/839) are high-mass ($\gtrsim$27 $M_\odot$). We detect no high-mass prestellar cores. The most massive cores (MMC) identified within individual clumps lack sufficient mass to form high-mass stars without additional mass feeding. We find that the mass of the MMCs is correlated with the clump surface density, implying denser clumps produce more massive cores and a larger number of cores. There is no significant mass segregation except for a few tentative detections. In contrast, most clumps show segregation once the clump density is considered instead of mass. Although the dust continuum emission resolves clumps in a network of filaments, some of which consist of hub-filament systems, the majority of the MMCs are not found in the hubs. Our analysis shows that high-mass cores and MMCs have no preferred location with respect to low-mass cores at the earliest stages of high-mass star formation.

The Atacama Large Millimeter/submillimeter Array (ALMA) revolutionised our understanding of protoplanetary discs. However, the available data have not given conclusive answers yet on the underlying disc evolution mechanisms (viscosity or MHD winds). Improving upon the current results, mostly based on the analysis of disc sizes, is difficult because larger, deeper and higher angular resolution surveys would be required, which could be prohibitive even for ALMA. In this Letter, we introduce an alternative method to study disc evolution based on $^{12}$CO fluxes. In fact, fluxes can be readily collected using less time-consuming, lower resolution observations, while tracing the same disc physico-chemical processes as sizes: assuming that $^{12}$CO is optically thick, fluxes scale with the disc surface area. We developed a semi-analytical model to compute $^{12}$CO fluxes and benchmarked it against the results of DALI thermochemical models, recovering an agreement within a factor of three. As a proof of concept we compared our models with Lupus and Upper Sco data, taking advantage of the increased samples, by a factor 1.3 (Lupus) and 3.6 (Upper Sco), when studying fluxes instead of sizes. Models and data agree well only if CO depletion is considered. However, the uncertainties on the initial conditions limited our interpretation of the observations. Our new method can be used to design future ad hoc observational strategies to collect better data and give conclusive answers on disc evolution.

As the sample size of repeating fast radio bursts (FRBs) has grown, an increasing diversity of phenomenology has emerged. Through long-term multi-epoch studies of repeating FRBs, it is possible to assess which phenomena are common to the population and which are unique to individual sources. We present a multi-epoch monitoring campaign of the repeating FRB source 20180301A using the ultra-wideband low (UWL) receiver observations with Murriyang, the Parkes 64-m radio telescope. The observations covered a wide frequency band spanning approximately 0.7--4 GHz, and yielded the detection of 46 bursts. None of the repeat bursts displayed radio emission in the range of 1.8--4 GHz, while the burst emission peaked at 1.1 GHz. We discover evidence for secular trends in the burst dispersion measure, indicating a rate of $-2.7\pm0.2\,{\rm pc\,cm^{-3}\,yr^{-1}}$. We also found significant variation in the Faraday rotation measure of the bursts across the follow-up period, including evidence of a sign reversal. While a majority of bursts did not exhibit any polarization, those that did show a decrease in the linear polarization fraction as a function of frequency, consistent with spectral depolarization due to scattering observed in other repeating FRB sources. Surprisingly, no significant variation in the polarization position angles was found, which is in contrast with earlier measurements reported for the FRB source. We measure the burst rate and sub-pulse drift rate variation and compare them with the previous results. These novel observations, along with the extreme polarization properties observed in other repeating FRBs, suggest that a sub-sample of FRB progenitors possess highly dynamic magneto-ionic environments.

We study the effects of the time-variable properties of thermonuclear X-ray bursts on modeling their millisecond-period burst oscillations. We apply the pulse profile modeling technique that is being used in the analysis of rotation-powered millisecond pulsars by the Neutron Star Interior Composition Explorer (NICER) to infer masses, radii, and geometric parameters of neutron stars. By simulating and analyzing a large set of models, we show that overlooking burst time-scale variability in temperatures and sizes of the hot emitting regions can result in substantial bias in the inferred mass and radius. To adequately infer neutron star properties, it is essential to develop a model for the time variable properties or invest a substantial amount of computational time in segmenting the data into non-varying pieces. We discuss prospects for constraints from proposed future X-ray telescopes.

Until recently it was thought that the nuclear stellar disc at the centre of our Galaxy was formed via quasi-continuous star formation over billions of years. However, an analysis of GALACTICNUCLEUS survey data indicates that >80% of the mass of the stellar disc formed at least 8 Gyr ago and about 5% roughly 1 Gyr ago. Our aim is to derive new constraints on the formation history of the nuclear stellar disc. We analysed a catalogue of HST/WFC3-IR observations of the Quintuplet cluster field. From this catalogue, we selected about 24000 field stars that probably belong to the nuclear stellar disc. We used red clump giants to deredden the sample and fit the resulting F153M luminosity function with a linear combination of theoretical luminosity functions created from different stellar evolutionary models. We find that >70% of the stellar population in the nuclear disc probably formed more than 10 Gyr ago, while ~15% formed in an event (or series of events) ~1Gyr ago. Up to 10% of the stars appear to have formed in the past tens to hundreds of Myr. These results do not change significantly for reasonable variations in the assumed mean metallicity, sample selection, reddening correction, or stellar evolutionary models. We confirm previous work that changed the formation paradigm for stars in the Galactic Centre. The nuclear stellar disc is indeed a very old structure. There seems to have been little star formation activity between its formation and about 1 Gyr ago.

Dynamical interactions involving binaries play a crucial role in the evolution of star clusters and galaxies. We continue our investigation of the hydrodynamics of three-body encounters, focusing on binary black hole (BBH) formation, stellar disruption, and electromagnetic (EM) emission in dynamical interactions between a BH-star binary and a stellar-mass BH, using the moving-mesh hydrodynamics code {\small AREPO}. This type of encounters can be divided into two classes depending on whether the final outcome includes BBHs. This outcome is primarily determined by which two objects meet at the first closest approach. BBHs are more likely to form when the star and the incoming BH encounter first with an impact parameter smaller than the binary's semimajor axis. In this case, the star is frequently disrupted. On the other hand, when the two BHs encounter first, frequent consequences are an orbit perturbation of the original binary or a binary member exchange. For the parameters chosen in this study, BBH formation, accompanied by stellar disruption, happens in roughly 1 out of 4 encounters. The close correlation between BBH formation and stellar disruption has possible implications for EM counterparts at the binary's merger. The BH that disrupts the star is promptly surrounded by an optically and geometrically thick disk with accretion rates exceeding the Eddington limit. If the debris disk cools fast enough to become long-lived, EM counterparts can be produced at the time of the BBH merger.

The sensitivity and wide area reached by ongoing and future wide-field optical surveys allows for the detection of an increasing number of galaxy clusters uniquely through their weak lensing (WL) signal. This motivates the development of new methods to analyse the unprecedented volume of data faster and more efficiently. Here we introduce a new multi-scale WL detection method based on application of wavelet filters to the convergence maps. We compare our results to those obtained from four commonly-used single scale approaches based on the application of aperture mass filters to the shear in real and Fourier space. The method is validated on Euclid-like mocks from the DUSTGRAIN-pathfinder simulations. We introduce a new matching procedure that takes into account the theoretical signal-to-noise of detection by WL and the filter size. We perform a complete analysis of the filters, and a comparison of the purity and the completeness of the resulting detected catalogues. We show that equivalent results are obtained when the detection is undertaken in real and Fourier space, and when the algorithms are applied to the shear and the convergence. We show that the multiscale method applied to the convergence is faster and more efficient at detecting clusters than single scale methods applied to the shear. We obtained an increase of 25% in the number of detections while maintaining the same purity compared to the most up-to-date aperture mass filter. We analyse the detected catalogues and quantify the efficiency of the matching procedure, showing in particular that less than 5% of the detections from the multiscale method can be ascribed to line-of-sight alignments. The method is well-adapted to the more sensitive, wider-area, optical surveys that will be available in the near future, and paves the way to cluster samples that are as near as possible to being selected by total matter content.

Thermonuclear supernovae, or Type-Ia supernovae (SNeIa), are an essential tool of cosmology. Precise cosmological constraints are extracted from a Hubble diagram defined by homogeneous distance indicators, but supernova homogeneity is not guaranteed. The degree of heterogeneity within the SNeIa parent population is unknown. In addition, event selections and standardization procedures are based on empirical, optically-measured observables rather than fundamental thermonuclear properties. Systematics are a natural consequence of event selection from a diverse parent population. Quantifying the impact of diversity-driven systematics is crucial to optimizing SNeIa as cosmic probes. In this work, the empirical observables are used to calibrate previously unidentified diversity-driven systematic uncertainties. The foundation of this approach is the concept of "supernova siblings'', two or more supernovae hosted by the same parent galaxy. Sibling-based calibrations isolate intrinsic differences between supernovae; they control for source distance and host galaxy dependencies that can conceal systematics or lead to their underestimation. Newly calibrated distance modulus uncertainties are approximately an order of magnitude larger than previously reported. The physical origin of these uncertainties is plausibly attributed to the diverse thermonuclear scenarios responsible for SNeIa and the inhomogeneous apparent magnitudes induced by this diversity. Systematics mitigation strategies are discussed. Cosmological parameter constraints extracted from a re-analysis of the Pantheon+ SNeIa dataset are weaker than previously reported. Agreement with early-Universe parameter estimates is achieved for a $\Lambda$CDM cosmology, including a reduction of the Hubble Tension from $\sim$5$\sigma$ to <1$\sigma$.

Wavelength-dependent atmospheric effects impact photometric supernova flux measurements for ground-based observations. We present corrections on supernova flux measurements from the Dark Energy Survey Supernova Program's 5YR sample (DES-SN5YR) for differential chromatic refraction (DCR) and wavelength-dependent seeing, and we show their impact on the cosmological parameters $w$ and $\Omega_m$. We use $g-i$ colors of Type Ia supernovae (SNe Ia) to quantify astrometric offsets caused by DCR and simulate point spread functions (PSFs) using the GalSIM package to predict the shapes of the PSFs with DCR and wavelength-dependent seeing. We calculate the magnitude corrections and apply them to the magnitudes computed by the DES-SN5YR photometric pipeline. We find that for the DES-SN5YR analysis, not accounting for the astrometric offsets and changes in the PSF shape cause an average bias of $+0.2$ mmag and $-0.3$ mmag respectively, with standard deviations of $0.7$ mmag and $2.7$ mmag across all DES observing bands (\textit{griz}) throughout all redshifts. When the DCR and seeing effects are not accounted for, we find that $w$ and $\Omega_m$ are lower by less than $0.004\pm0.02$ and $0.001\pm0.01$ respectively, with $0.02$ and $0.01$ being the $1\sigma$ statistical uncertainties. Although we find that these biases do not limit the constraints of the DES-SN5YR sample, future surveys with much higher statistics, lower systematics, and especially those that observe in the $u$ band will require these corrections as wavelength-dependent atmospheric effects are larger at shorter wavelengths. We also discuss limitations of our method and how they can be better accounted for in future surveys.

New spectroscopic orbits of inner subsystems in 14 hierarchies are determined from long-term monitoring with the optical echelle spectrometer, CHIRON. Their main components are nearby solar-type stars belonging to nine triple systems (HIP 3645, 14307, 36165, 79980, 103735, 103814, 104440, 105879, 109443) and five quadruples of 2+2 hierarchy (HIP 41171, 49336, 75663, 78163, and 117666). The inner periods range from 254 days to 18 yr. Inner subsystems in HIP 3645, 14313, 79979, 103735, 104440, and 105879 are resolved by speckle interferometry, and their combined spectro-interferometric orbits are derived here. Astrometric orbits of HIP 49336 Aa,Ab and HIP 117666 Aa,Ab are determined from wobble in the observed motion of the outer pairs. Comparison with three spectroscopic orbits found in the Gaia DR3 archive reveals that Gaia under-estimated the amplitudes (except for HIP 109443), while the periods match approximately. This work contributes new data on the architecture of nearby hierarchical systems, complementing their statistics.

Orbital motions in four hierarchical stellar systems discovered by speckle interferometry are studied. Their inner orbits are relatively well constrained, while the long outer orbits are less certain. The eccentric and misaligned inner orbits in the early-type hierarchies Epsilon Cha (B9V, central star of the 5 Myr old association, P=6.4 yr, e=0.73), and I~385 (A0V, P~300 yr, e~0.8) suggest past dynamical interactions. Their nearly equal masses could be explained by a dynamical decay of a 2+2 quadruple progenitor consisting of four similar stars. However, there is no evidence of the associated recoil, so similar masses could be just a consequence of accretion from the same core. The other two hierarchies, HIP 32475 (F0IV, inner period 12.2 yr) and HIP 42910 (K7V, inner period 6.8 yr), have smaller masses and are double twins where both inner and outer mass ratios are close to one. A double twin could either result from a merger of one inner pair in a 2+2 quadruple or can be formed by a successive fragmentation followed by accretion.

Aegaeon (S/2008 S 1) is the last satellite discovered by the Cassini spacecraft at the end of the 2000s. Like the satellites Methone and Anthe, it is involved in mean motion resonance with the mid-sized Mimas. In this work, we give a detailed analysis of the current orbit of Aegaeon identifying the resonant, secular and long-term perturbations due to Mimas and the oblateness of Saturn, and the effects of Tethys. For this task, we perform thousands of numerical simulations of full equations of motion of ensembles of small bodies representing clones of Aegaeon. We have mapped the domain of the 7:6 Mimas-Aegaeon resonance in the phase space of the semi-major axis and eccentricity. It displays a large area dominated by regular motions associated with the 7:6 corotation resonance surrounded by chaotic layers. Aegaeon is currently located very close to the periodic orbit of the resonance, which extends up to eccentricities $\sim0.025$ centered at semi-major axis $\sim168,028$ km. We show that the current orbit of Aegaeon has an important forced component in eccentricity due to the 7:6 resonance. The orbital inclination of Aegaeon has a non-negligible forced value due to long-term perturbations of Mimas. These two forced modes explain the complex perturbed orbit of Aegaeon without requiring the co-existence of multiple resonances.

We use the rapid binary stellar evolution code $\texttt{binary_c}$ to estimate the rate of merging neutron stars with numerous combinations of envelope ejection efficiency and natal kick dispersion. We find a peak in the local rate of merging neutron stars around $\alpha \approx 0.3$$-$$0.4$, depending on the metallicity, where $\alpha$ is the efficiency of utilising orbital energy to unbind the envelope. The peak height decreases with increasing electron-capture supernova kick dispersion $\sigma_\mathrm{ECSN}$. We explain the peak as a competition between the total number of systems that survive the common-envelope phase increasing with $\alpha$ and their separation, which increases with $\alpha$ as well. Increasing $\alpha$ reduces the fraction of systems that merge within a time shorter than the age of the Universe and results in different mass distributions for merging and non-merging double neutron stars. This offers a possible explanation for the discrepancy between the Galactic double neutron star mass distribution and the observed massive merging neutron star event GW190425. Within the $\alpha$$-$$\sigma_\mathrm{ECSN}$ parameter space that we investigate, the rate of merging neutron stars spans several orders of magnitude up to more than $1\times 10^{3} \, \mathrm{Gpc}^{-3}\,\mathrm{yr}^{-1}$ and can be higher than the observed upper limit or lower than the observed lower limit inferred thus far from merging neutron stars detected by gravitational waves. Our results stress the importance of common-envelope physics for the quantitative prediction and interpretation of merging binary neutron star events in this new age of gravitational wave astronomy.

We study the gravitational Bose-Einstein condensation of a massive vector field in the kinetic regime and the non-relativistic limit using non-linear dynamical numerical methods. Gravitational condensation leads to the spontaneous formation of solitons. We measure the condensation time and growth rate, and compare to analytical models in analogy to the scalar case. We find that the condensation time of the vector field depends on the correlation between its different components. For fully correlated configurations, the condensation time is the same as that for a scalar field. On the other hand, uncorrelated or partially correlated configurations condense slower than the scalar case. As the vector soliton grows, it acquires a net spin angular momentum even if the total spin angular momentum of the initial conditions is zero.

Planetary nebulae (PNe) consist of an ionized envelope surrounding a hot central star (CSPN) that emits mostly at ultraviolet (UV) wavelengths. Ultraviolet observations, therefore, provide important information on both the CSPN and the nebula. We have matched the PNe in The Hong Kong/AAO/Strasbourg H$\alpha$ (HASH) catalog with the Galaxy Evolution Explorer (GALEX) UV sky surveys, the Sloan Digital Sky Survey data release 16 (SDSS), and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) PS1 second release. A total of 671 PNe were observed by GALEX with the far-UV (FUV; 1344-1786{\AA}) and/or the near-UV (NUV; 1771-2831{\AA}) detector on (GUVPNcat); 83 were observed by SDSS (PNcatxSDSSDR16) and 1819 by Pan-STARRS (PNcatxPS1MDS). We merged a distilled version of these matched catalogs into GUVPNcatxSDSSDR16xPS1MDS, which contains a total of 375 PNe with both UV and optical photometry over a total spectral coverage of $\sim$1540--9610{\AA}. We analysed separately 170 PNe resolved in GALEX images and determined their UV radius by applying a flux profile analysis. The CSPN flux could be extracted separately from the PN emission for 8 and 50 objects with SDSS and Pan-STARRS counterparts respectively. The multi-band photometry was used to distinguish between compact and extended PNe and CSPNe (binary CSPNe) by color--color diagram analysis. We found that compact PNe candidates could be identified by using the $r-i < -0.4$ and $-$1$<$FUV$-$NUV$<$1 colors, whereas binary CSPNe candidates in given $T_\mathrm{eff}$ ranges (all with color r$-$i$>-$0.4) can be identified in the color region (FUV$-$NUV)$\leq$6(r$-$i)+1.3, $-$0.8$<$FUV$-$NUV$<$0.4 and r$-$i$<$0.75.

We study the importance of the thermal behavior of the hadron-quark phase transition in neutron star (NS) mergers. To this end, we devise a new scheme approximating thermal effects to supplement any cold, barotropic hybrid equation of state (EoS) model, i.e. two-phase EoS constructions with a hadronic regime and a phase of deconfined quark matter. The consideration of temperature-dependent phase boundaries turns out to be critical for a quantitative description of quark matter effects in NS mergers, since the coexistence phase can introduce a strong softening of the EoS at finite temperature, which is even more significant than the change of the EoS by the phase transition at T=0. We validate our approach by comparing to existing fully temperature-dependent EoS models and find a very good quantitative agreement of postmerger gravitational-wave (GW) features. Simulations with the commonly-used thermal ideal-gas approach exhibit sizable differences compared to full hybrid models implying that its use in NS merger simulations with quark matter is problematic. Our new scheme provides the means to isolate thermal effects of quark matter from the properties of the cold hybrid EoS and thus allows an assessment of the thermal behavior alone. We show that different shapes of the phase boundaries at finite temperature can have a large impact on the postmerger dynamics and GW signal for the same cold hybrid model. This finding demonstrates that postmerger GW emission contains important complementary information compared to properties extracted from cold stars. We also show by concrete examples that it is even possible for quark matter to only occur and thus be detectable in finite-temperature systems like merger remnants but not in cold NSs.

Using wave kinetics, we estimate the emergence time-scale of gravitating Bose-Einstein condensates/Bose stars in the kinetic regime for a general multicomponent Schr\"{o}dinger-Poisson (SP) system. We identify some effects of the diffusion and friction pieces in the wave-kinetic Boltzmann equation (at leading order in perturbation theory) and provide estimates for the kinetic nucleation rate of condensates. We test our analysis using full $3+1$ dimensional simulations of multicomponent SP system. With an eye towards applications to multicomponent dark matter, we investigate two general cases in detail. First is a massive spin-$s$ field with $N=2s+1$ components (scalar $s=0$, vector $s=1$ and tensor $s=2$). We find that for a democratic population of different components, the condensation time-scale is $\tau_{(s)}\approx \tau_0\times N$, where $\tau_0$ is the condensation time scale for the scalar case. Second is the case of two scalars with different boson masses. In this case, we map-out how the condensation time depends on the ratios of their average mass densities and boson masses, revealing competition and assistance between components, and a guide towards which component condenses first. For instance, with $m_1 < m_2$ and not too disparate mass densities, we verify that the time scale of condensation of the first species quickly becomes independent of $m_2/m_1$, whereas for equal average number densities, the emergence time scale decreases with increasing $m_2/m_1$.

Dust extinction is one of the fundamental measurements of dust grain sizes, compositions, and shapes. Most of the wavelength dependent variations seen in Milky Way extinction are strongly correlated with the single parameter R(V)=A(V)/E(B-V). Existing R(V) dependent extinction relationships use a mixture of spectroscopic and photometry observations, hence do not fully capture all the important dust features nor continuum variations. Using four existing samples of spectroscopically measured dust extinction curves, we consistently measure the R(V) dependent extinction relationship spectroscopically from the far-ultraviolet to mid-infrared for the first time. Linear fits of A(lambda)/A(V) dependent on R(V) are done using a method that fully accounts for their significant and correlated uncertainties. These linear parameters are fit with analytic wavelength dependent functions to determine the smooth R(V) (2.3-5.6) and wavelength (912 A-32 micron) dependent extinction relationship. This relationship shows that the far-UV rise, 2175 A bump, and the three broad optical features are dependent on R(V), but the 10 and 20 micron features are not. Existing literature relationships show significant deviations compared to this relationship especially in the far-ultraviolet and infrared. Extinction curves that clearly deviate from this relationship illustrate that this relationship only describes the average behavior versus R(V). We find tentative evidence that the relationship may not be linear with 1/R(V) especially in the ultraviolet. For the first time, this relationship provides measurements of dust extinction that spectroscopically resolve the continuum and features in the ultraviolet, optical, and infrared as a function of R(V) enabling detailed studies of dust grains properties and full spectroscopic accounting for the effects of dust extinction on astrophysical objects.

All single-field inflationary models invoke varying degrees of tuning in order to account for cosmological observations. Mechanisms that generate primordial black holes (PBHs) from enhancement of primordial power at small scales posit inflationary potentials that transiently break scale invariance and possibly adiabaticity over a range of modes. This requires additional tuning on top of that required to account for observations at scales probed by cosmic microwave background (CMB) anisotropies. In this paper we study the parametric dependence of various single-field models of inflation that enhance power at small scales and quantify the degree to which coefficients in the model construction have to be tuned in order for certain observables to lie within specified ranges. We find significant tuning: changing the parameters of the potentials by between one part in a hundred and one part in $10^8$ (depending on the model) is enough to change the power spectrum peak amplitude by an order one factor. The fine-tuning of the PBH abundance is larger still by 1-2 orders of magnitude. We highlight the challenges imposed by this tuning on any given model construction. Furthermore, polynomial potentials appear to require significant additional fine-tuning to also match the CMB observations.

The EnVision and VERITAS missions to Venus will fly with X and Ka band telecommunications channels which can be used to conduct radio occultation studies of Venus' atmosphere. While link attenuation measurements during prior S and X band occultation experiments have been used to determine vertical profiles of H$_2$SO$_4$ vapor abundance, the addition of the Ka band channel introduces greater sensitivity to the abundances of H$_2$SO$_4$ aerosols and SO$_2$ gas, permitting retrieval of their vertical profiles from dual band measurements. Such measurements would be valuable in the assessment of chemical and dynamical processes governing short and long-term variability in Venus' atmosphere. This paper considers the sensitivity of the X/Ka band radio attenuation measurement to these atmospheric constituents, as well as uncertainties and regularization approaches for conducting retrievals of these atmospheric sulfur species from future occultation experiments. We introduce methods for seeding maximum likelihood estimation retrievals using shape models and simple atmospheric transport constraints. From simulated retrievals, we obtain mean errors of the order of 0.5 ppm, 20 ppm, and 10 mg/m$^3$ for H$_2$SO$_4$ vapor, SO$_2$, and H$_2$SO$_4$ aerosol abundances, respectively, for simultaneous retrieval.

We study satellite counts and quenched fractions for satellites of Milky Way analogs in Romulus25, a large-volume cosmological hydrodynamic simulation. Depending on the definition of a Milky Way analog, we have between 66 and 97 Milky Way analogs in Romulus25, a 25 Mpc-per-side uniform volume simulation. We use these analogs to quantify the effect of environment and host properties on satellite populations. We find that the number of satellites hosted by a Milky Way analog increases with host stellar mass, while there is no trend with environment, as measured by distance to a Milky Way-mass or larger halo. Similarly, we find that the satellite quenched fraction for our analogs also increases with host stellar mass, with no significant impact from environment. We place these results in the context of observations through comparisons to the ELVES and SAGA surveys. Our results are robust to changes in Milky Way analog selection criteria, including those that mimic observations. Finally, as our samples naturally include Milky Way/Andromeda pairs, we examine quenched fractions in pairs vs isolated systems. We find potential evidence, though not conclusive, that pairs may have higher satellite quenched fractions.

4D mathematical models of structurally related (conjugated, entangled, dual) phenomena of dissipation and cumulation of electrical energy (an external source in continuous media) are discussed, accompanied by the formation of cumulative-dissipative structures and their ordering into a regular system - a dynamic dissipative "crystal" with a long-range dynamic order. The excitation of new degrees of freedom in such systems provides attractiveness or geometric self-focusing of energy-mass-momentum flows (EMMF) for the entire regular system. As a result of cumulation, EMMF structures acquire hyper-properties. The cumulation of EMMF in rendered structures is a common property of media activated to form 4D structures. The basis of such a dissipative structure is an attractor, the end result of which is a cumulative jet from an attractor with hyper-properties. Therefore, these structures are cumulative-dissipative. We discuss a method for describing these structures and prove that cumulative processes in plasmoids exist and can be described theoretically, although not with the help of full-fledged mathematical 4D models. It has been theoretically and experimentally proven that the cumulation of the electric field due to the ambipolar drift of the plasma is an inherent property of the current carrying gas-discharge plasma. The results obtained by modeling shock waves of the electric field (E/N) can be useful to explain the cumulative formation in the heliosphere, atmosphere and ionosphere of the Earth, since the Earth has a negative charge of about 500,000 C, and the Sun positively charged at the level of 1400 C. Based on the mathematical approach, a classification of shock waves and types of cumulation in 4D space-time will be carried out.

We study extreme-mass-ratio systems in theories admitting the Schwarzschild solution and propagating a massive graviton. We show that, in addition to small corrections to the quadrupolar and higher-order modes, a dipolar mode is excited in these theories and we quantify its excitation. While LIGO-Virgo-KAGRA observations are not expected to impose meaningful constraints in the dipolar sector, future observations by the Einstein Telescope or by LISA, together with bounds from dispersion relations, can rule out theories of massive gravity admitting vacuum General Relativistic backgrounds. For the bound to be circumvented, one needs to move away from Ricci-flat solutions, and enter a territory where constraints based on wave propagation and dispersion relations are not reliable.

Due to coherent superradiant amplification, massive bosonic fields can trigger an instability in spinning black holes, tapping their energy and angular momentum and forming macroscopic Bose-Einstein condensates around them. This phenomenon produces gaps in the mass-spin distribution of astrophysical black holes, a continuous gravitational-wave signal emitted by the condensate, and several environmental effects relevant for gravitational-wave astronomy and radio images of black holes. While the spectrum of superradiantly unstable mode is known in great detail for massive scalar (spin-0) and vector (spin-1) perturbations, so far only approximated results were derived for the case of massive tensor (spin-2) fields, due to the nonseparability of the field equations. Here, solving a system of ten elliptic partial differential equations, we close this program and compute the spectrum of the most unstable modes of a massive spin-2 field for generic black-hole spin and boson mass, beyond the hydrogenic approximation and including the unique dipole mode that dominates the instability in the spin-2 case. We find that the instability timescale for this mode is orders of magnitude shorter than for any other superradiant mode, yielding much stronger constraints on massive spin-2 fields. These results pave the way for phenomenological studies aimed at constraining beyond Standard Model scenarios, ultralight dark matter candidates, and extensions to General Relativity using gravitational-wave and electromagnetic observations, and have implications for the phase diagram of vacuum solutions of higher-dimensional gravity.

We study the non-perturbative evolution of inflationary fluctuations during preheating using fully non-linear general-relativistic field-theory simulations. We choose a single-field inflationary model that is consistent with observational constraints and start the simulations at the end of inflation with fluctuations both in the field and its conjugate momentum. Gravity enhances the growth of density perturbations, which then collapse and virialize, forming long-lived stable oscillon-like stars that reach compactnesses $\mathcal{C}\equiv GM/R \sim 10^{-3}-10^{-2}$. We find that $\mathcal{C}$ increases for larger field models, until it peaks due to the interplay between the overdensity growth and Hubble expansion rates. Whilst gravitational effects can play an important role in the formation of compact oscillons during preheating, the objects are unlikely to collapse into primordial black holes without an additional enhancement of the initial inflationary fluctuations.

The rapid neutron capture or 'r process' of nucleosynthesis is believed to be responsible for the production of approximately half the natural abundance of heavy elements found on the periodic table above iron (with proton number $Z=26$) and all of the heavy elements above bismuth ($Z=83$). In the course of creating the actinides and potentially superheavies, the r process must necessarily synthesize superheavy nuclei (those with extreme proton numbers, neutron numbers or both) far from isotopes accessible in the laboratory. Many questions about this process remain unanswered, such as 'where in nature may this process occur?' and 'what are the heaviest species created by this process?' In this review, we survey at a high level the nuclear properties relevant for the heaviest elements thought to be created in the r process. We provide a synopsis of the production and destruction mechanisms of these heavy species, in particular the actinides and superheavies, and discuss these heavy elements in relation to the astrophysical r process. We review the observational evidence of actinides found in the Solar system and in metal-poor stars and comment on the prospective of observing heavy-element production in explosive astrophysical events. Finally, we discuss the possibility that future observations and laboratory experiments will provide new information in understanding the production of the heaviest elements.

It has been shown recently that quark-hadron conversions at the interface of a hybrid star may have a key role on the dynamic stability of the compact object. In this work we perform a systematic study of hybrid stars with reactive interfaces using a model-agnostic piecewise-polytropic hadronic equation of state and the Nambu-Jona-Lasinio model for three-flavor quark matter. For the hadronic phase we use a soft, an intermediate and a stiff parametrization that match at $1.1 n_0$ {with predictions} based on chiral effective field theory (cEFT) interactions. In the NJL Lagrangian we include scalar, vector and 't Hooft interactions. The vector coupling constant $g_{v}$ is treated as a free parameter. We also consider that there is a split between the deconfinement and the chiral phase transitions which is controlled by changing the conventional value of the vacuum pressure $-\Omega_{0}$ in the NJL thermodynamic potential by $-\left(\Omega_{0}+\delta \Omega_{0}\right)$, being $\delta \Omega_{0}$ a free parameter. We analyze the mass-radius ($M$-$R$) relation in the case of rapid ($\tau \ll 1 \, \mathrm{ms}$) and slow ($\tau \gg 1 \, \mathrm{ms}$) conversions, being $\tau$ the reaction timescale. In the case of slow interface reactions we find $M$-$R$ curves with a cusp at the maximum mass point where a pure hadronic branch and a slow-stable hybrid star (SSHS) branch coincide. We find that the length of the slow-stable branch grows with the increase of the transition density and the energy density jump at the hadron-quark interface. We calculate the tidal deformabilities of SSHSs and analyse them in the light of the GW170817 event.